The present invention relates to a dispenser device for dispensing a predetermined dose of liquid. More particularly, the invention relates to a device which contains a single dose of liquid, and which is discardable after said dose has been emitted. The liquid to be delivered may be a medicine, a cosmetic, or the like. The device of the invention is designed, in particular, for nose sprays, but could be used for other purposes, such as for ear sprays, mouth sprays, etc.
Such devices are known in the prior art. For example, document EP-A-0 311 863 describes a device including a cylinder of liquid in which a piston slides, the piston being secured to an actuating pushbutton. The device further includes an outlet passage which communicates with the cylinder of liquid. However, the outlet passage is not airtight and the liquid contained in the cylinder can become oxidized or polluted during storage on coming into contact with the air.
To solve that problem, document WO 93/00172 provides a movable piston in the cylinder, so that in the storage position, it cuts off communication between the outlet passage and the cylinder, and in the actuated position, it puts said outlet passage into communication with said cylinder, said piston being blocked in its storage position, and being displaced towards its actuated position in order to free the outlet passage, only if sufficient pressure appears in the cylinder to unblock it. However, that implementation, which operates in satisfactory manner, presents a certain number of drawbacks. Thus, in order to be able to determine in advance the level of pressure that is sufficient to unblock the piston, the dimensions of the piston must be very accurate to ensure effective blocking in the storage position, and guaranteed freeing when the device is actuated. This can turn out to be relatively difficult because of the dimensional tolerances that appear during manufacture of the various components parts of the device. Furthermore, manufacture and assembly of the piston itself are relatively complicated and therefore costly, thereby substantially increasing the cost of the device, particularly when the device is discardable after a single actuation. In addition, the presence of said piston, which is a movable element relative to all the other component parts of the device, represents a complication and therefore an undesirable increase in the cost of manufacturing and assembling the device.
Document WO 91/13281 describes a device including the characteristics mentioned in the preamble of claim 1.
An object of the present invention is to make a device of the above-mentioned type which does not have the above-mentioned drawbacks. In particular, the object of the present invention is to provide such a device which is simple and cheap to manufacture and assemble. This is particularly advantageous for devices which are discarded after a single actuation. Another object of the present invention is to provide such a device which guarantees total sealing during storage, and guarantees that the dose of liquid is dispensed in full when the device is actuated. Another object of the present invention is to provide such a device in which empty space is minimized. Another object of the present invention is to provide such a device which includes a minimum of independently movable parts.
The present invention therefore provides a dispenser device for dispensing a single dose of liquid, said device comprising a cylinder containing said dose of liquid, a piston which slides in sealed manner in said cylinder between a storage position in which it isolates said cylinder and an actuated position, a piston actuator member, an outlet passage for connecting said cylinder to an outlet orifice, and a spray nozzle which is disposed in the outlet passage for spraying the dose of liquid, said piston including a through-passage which is closed in sealed manner in the storage position of the piston by a closure member, said closure member being designed to open said through-passage under the effect of a predetermined pressure which is created inside the cylinder, so as to enable said dose of liquid to be expelled through said through-passage, the device being characterized in that said closure member is secured to said spray nozzle, said spray nozzle being movable between an initial position corresponding to the closed position of the closure member, and a final position corresponding to the open position of the closure member.
Said closure member is preferably movable between a closed position, in which it is disposed in said through-passage, and an open position, in which it is expelled out from said through-passage.
Advantageously, said through-passage is at least partially cylindrical, and said closure member has outside dimensions that are greater than the cross section of said through-passage so that it is blocked in the closed position, said closure member being expelled out from said through-passage under the effect of said sufficient pressure which is created in the cylinder.
In a particular embodiment of the invention, said through-passage includes a cavity designed to receive said closure member in its closed position.
The walls which form the through-passage of the piston are preferably deformable under the effect of a pressure that is sufficient to enable said closure member to be expelled.
In particular, said closure member may be a ball-bearing.
The spray nozzle advantageously includes an end portion which extends into said cylinder when the spray nozzle is in its initial position, said end portion being designed to occupy, at least in part, the empty space created in the through-passage when the spray nozzle is in its final position.
Said cylinder is advantageously made of glass.
Said piston is preferably fixed relative to said actuator member and is displaced in the cylinder together with said actuator member.
Said through-passage advantageously includes a substantially cylindrical first portion and a substantially cylindrical second portion, the cross section of said second portion being greater than that of said first portion, said closure member having outside dimensions which are greater than said section of the first portion and which are less than said cross section of the second portion.